Hentai narrow Japanese usage and broad international usage are often incompatible. The term is typically used by the cinematographer within the narrative framework of a pornographic film, and since the 1970s has become a leitmotif of the hardcore genre. These actors often play the top roles but this is not always the case, such as with Kristen Bjorn and some Bel Ami models. A person young gay porn may be sexually penetrated multiple times simultaneously. Patricia Hill Collins, an African-American writer, theorizes that this is derived from a stereotype that those of black descent are promiscuous, big tit milf and their buttocks are objectified by porn as a result. Milking pornography features lactating women being milked or milking themselves . Crush pornography features objects being crushed by an actress or actor, who generally plays an overtly dominant role. In general, as compared to conventional relationships, BDSM participants go to great lengths to negotiate the important aspects of their relationships in advance, and to take great care in learning about and following safe practices. The consensual submission of the submissive is sometimes demonstrated to others by symbols indicating his/her belonging to the dominant, such as wearing a collar, special tattoos, piercings, a very short haircut or a bald head. Instead, all five fingers are kept straight and held as close together as possible , then slowly inserted into a well lubricated vagina or rectum. Coprophilia , also called scatophilia or scat , is the paraphilia involving sexual arousal and pleasure from feces. Certain websites have begun providing bondage videos and photographs featuring the kidnapping roleplay, which has been largely the hallmark of detective style bondage magazines. Erotic spankings are commonly combined with other forms of sexual foreplay. In some hentai porn creampie films, both gay and straight, intercourse and internal ejaculation are followed by performers licking up the semen that has dripped from their bodies. Some pornographic films use an artificial semen substitute to simulate or enhance creampie shots.